Recently, a series of urban diseases have seriously impacted the development of large and medium cities. The development of urban underground space (UUS) is widely regarded as an effective solution. Due to the irreversibility of underground space resources, it is important to formulate scientific and reasonable development planning based on evaluation of the development potential of urban underground space (DPUUS). In this work, from the perspective of society, economy, and environment, an evaluation model of the DPUUS was established, and nine indexes were selected, including population density, vehicle possessive quantity per 100 capita, policy support, GDP per capita, GDP per km², land price, geographical position, geological conditions, and natural disasters. The comprehensive weight method (CWM) combined with subjective and objective weights was used to determine the final weight of the evaluation index. Set pair analysis (SPA) and the credible degree recognition criterion (CDRC) were applied to determine the DPUUS grade of each city, which can provide a new idea for DPUUS.

The development and utilization of urban underground space (UUS) have emerged as critical strategies to address the challenges posed by urban population growth and land resource depletion. Accurate prediction of UUS demand serves as the cornerstone for scientifically planning underground space and promoting sustainable urban development. In this study, statistical analysis methods were used to investigate the relationship between potential driving factors and UUS demand based on collected data from 16 cities in China. The identification of primary driving factors involves correlation, path, and determination coefficient analyses. Subsequently, univariate regression, multiple linear regression, and LASSO regression methods are employed to construct prediction models for UUS demand. Additionally, the link between historical data and UUS demand in each city was studied separately. The findings reveal that GDP per km² and GDP per capita comprehensively capture the influence of urban population, economy, and transportation on UUS demand. Notably, GDP per km² makes the most significant contribution to the proposed regression models, followed by GDP per capita. The application of LASSO regression proves effective in selecting potential factors while maximizing data utilization, presenting itself as a valuable auxiliary tool for UUS planning.

The strength anisotropy for inherent anisotropic rocks presents a challenge to simulate considering the influence of intermediate principal stress. Based on the modified Lade failure criterion, a new anisotropic modified Lade criterion combining an empirical equation is established and verified using published experimental datasets of anisotropic rocks. The incremental constitutive model for anisotropic rocks is derived by using finite difference theory. The dynamic link library (DLL) module of the model is obtained by using the VC++ program, and then the model is validated against various laboratory test results. It is concluded that the proposed criterion and derived model can describe the strength anisotropy of inherent anisotropic rocks well.

Modified Lade criterion can not only describe the strength properties of many kinds of rocks well but also has simple and practical parameters. Although the elastoplastic solution of circular tunnel has been extensively investigated, the method based on modified Lade criterion considering the effect of the intermediate principal stress, strain‐softening behavior, and dilatancy has not yet been studied. In this paper, a new numerical procedure based on modified Lade criterion is proposed to calculate the elastoplastic solutions for surrounding rock of the circular tunnel. The comparisons of stress, displacement, and plastic zone radius are carried out between the presented method and published literatures under axisymmetric and nonaxisymmetric original in situ stress field. Finally, a series of parametric analyses are executed and discussed. It can be concluded that the lateral pressure coefficient, λ, influences both the size of plastic zone and the development direction. The plastic zone radius shows a negative power function change with increasing critical deviatoric plastic strain and increases slightly with increasing dilation angle, ψ.